I've noticed a lot of my favorite designs in Pokemon are those that are missing key facial features. I just find something about that concept works in monster design to make them a little more intriguing and alien yet endearing. Aromatisse doesn't have the mouth. Magnemite only has an eye. Starmie has nothing but a gem. Generally I think a lack of mouth makes for the most interesting followed by eyes and then nose. Machamp is still great but eyes and mouth are just so expressive it doesn't have the same unsettling allure of a Pokemon that's all eyes in their emotion like Poliwhirl. Though I think it does still work, take Perrserker for example. Gen VIII has been rather disappointing in this regard unfortunately with only Falink somewhat having that vibe.
Do you feel the same way and have any favorite examples of this in Pokemon?